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vf_aspect.c
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1 /*
2  * Copyright (c) 2010 Bobby Bingham
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * aspect ratio modification video filters
24  */
25 
26 #include <float.h>
27 
28 #include "libavutil/common.h"
29 #include "libavutil/eval.h"
30 #include "libavutil/mathematics.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/parseutils.h"
33 #include "libavutil/pixdesc.h"
34 
35 #include "avfilter.h"
36 #include "internal.h"
37 #include "video.h"
38 
39 static const char *const var_names[] = {
40  "w",
41  "h",
42  "a", "dar",
43  "sar",
44  "hsub",
45  "vsub",
46  NULL
47 };
48 
49 enum var_name {
57 };
58 
59 typedef struct AspectContext {
60  const AVClass *class;
63  int max;
64  char *ratio_expr;
66 
68 {
69  AspectContext *s = link->dst->priv;
70 
71  frame->sample_aspect_ratio = s->sar;
72  return ff_filter_frame(link->dst->outputs[0], frame);
73 }
74 
75 #define OFFSET(x) offsetof(AspectContext, x)
76 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
77 
78 static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
79 {
80  if (sar.num && sar.den) {
81  av_reduce(&dar->num, &dar->den, sar.num * w, sar.den * h, INT_MAX);
82  } else {
83  av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
84  }
85 }
86 
87 static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
88 {
89  AVFilterContext *ctx = inlink->dst;
90  AspectContext *s = inlink->dst->priv;
92  double var_values[VARS_NB], res;
93  int ret;
94 
95  var_values[VAR_W] = inlink->w;
96  var_values[VAR_H] = inlink->h;
97  var_values[VAR_A] = (double) inlink->w / inlink->h;
98  var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
99  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
100  var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
101  var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
102  var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
103 
104  /* evaluate new aspect ratio*/
105  ret = av_expr_parse_and_eval(&res, s->ratio_expr,
106  var_names, var_values,
107  NULL, NULL, NULL, NULL, NULL, 0, ctx);
108  if (ret < 0) {
109  ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
110  } else
111  *aspect_ratio = av_d2q(res, s->max);
112 
113  if (ret < 0) {
114  av_log(ctx, AV_LOG_ERROR,
115  "Error when evaluating the expression '%s'\n", s->ratio_expr);
116  return ret;
117  }
118  if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
119  av_log(ctx, AV_LOG_ERROR,
120  "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
121  return AVERROR(EINVAL);
122  }
123  return 0;
124 }
125 
126 #if CONFIG_SETDAR_FILTER
127 
128 static int setdar_config_props(AVFilterLink *inlink)
129 {
130  AspectContext *s = inlink->dst->priv;
131  AVRational dar;
132  AVRational old_dar;
133  AVRational old_sar = inlink->sample_aspect_ratio;
134  int ret;
135 
136  if ((ret = get_aspect_ratio(inlink, &s->dar)))
137  return ret;
138 
139  if (s->dar.num && s->dar.den) {
140  av_reduce(&s->sar.num, &s->sar.den,
141  s->dar.num * inlink->h,
142  s->dar.den * inlink->w, INT_MAX);
143  inlink->sample_aspect_ratio = s->sar;
144  dar = s->dar;
145  } else {
146  inlink->sample_aspect_ratio = (AVRational){ 1, 1 };
147  dar = (AVRational){ inlink->w, inlink->h };
148  }
149 
150  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
151  av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
152  inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
153  dar.num, dar.den, inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den);
154 
155  return 0;
156 }
157 
158 static const AVOption setdar_options[] = {
159  { "dar", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
160  { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
161  { "r", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
162  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
163  { NULL }
164 };
165 
166 AVFILTER_DEFINE_CLASS(setdar);
167 
168 static const AVFilterPad avfilter_vf_setdar_inputs[] = {
169  {
170  .name = "default",
171  .type = AVMEDIA_TYPE_VIDEO,
172  .config_props = setdar_config_props,
173  .filter_frame = filter_frame,
174  },
175  { NULL }
176 };
177 
178 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
179  {
180  .name = "default",
181  .type = AVMEDIA_TYPE_VIDEO,
182  },
183  { NULL }
184 };
185 
186 AVFilter ff_vf_setdar = {
187  .name = "setdar",
188  .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
189  .priv_size = sizeof(AspectContext),
190  .priv_class = &setdar_class,
191  .inputs = avfilter_vf_setdar_inputs,
192  .outputs = avfilter_vf_setdar_outputs,
193 };
194 
195 #endif /* CONFIG_SETDAR_FILTER */
196 
197 #if CONFIG_SETSAR_FILTER
198 
199 static int setsar_config_props(AVFilterLink *inlink)
200 {
201  AspectContext *s = inlink->dst->priv;
202  AVRational old_sar = inlink->sample_aspect_ratio;
203  AVRational old_dar, dar;
204  int ret;
205 
206  if ((ret = get_aspect_ratio(inlink, &s->sar)))
207  return ret;
208 
209  inlink->sample_aspect_ratio = s->sar;
210 
211  compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
212  compute_dar(&dar, s->sar, inlink->w, inlink->h);
213  av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
214  inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
215  inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den, dar.num, dar.den);
216 
217  return 0;
218 }
219 
220 static const AVOption setsar_options[] = {
221  { "sar", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
222  { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
223  { "r", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
224  { "max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
225  { NULL }
226 };
227 
228 AVFILTER_DEFINE_CLASS(setsar);
229 
230 static const AVFilterPad avfilter_vf_setsar_inputs[] = {
231  {
232  .name = "default",
233  .type = AVMEDIA_TYPE_VIDEO,
234  .config_props = setsar_config_props,
235  .filter_frame = filter_frame,
236  },
237  { NULL }
238 };
239 
240 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
241  {
242  .name = "default",
243  .type = AVMEDIA_TYPE_VIDEO,
244  },
245  { NULL }
246 };
247 
248 AVFilter ff_vf_setsar = {
249  .name = "setsar",
250  .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
251  .priv_size = sizeof(AspectContext),
252  .priv_class = &setsar_class,
253  .inputs = avfilter_vf_setsar_inputs,
254  .outputs = avfilter_vf_setsar_outputs,
255 };
256 
257 #endif /* CONFIG_SETSAR_FILTER */
int av_parse_ratio(AVRational *q, const char *str, int max, int log_offset, void *log_ctx)
Parse str and store the parsed ratio in q.
Definition: parseutils.c:45
#define NULL
Definition: coverity.c:32
#define OFFSET(x)
Definition: vf_aspect.c:75
const char * s
Definition: avisynth_c.h:768
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2359
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
AVOption.
Definition: opt.h:246
static const char *const var_names[]
Definition: vf_aspect.c:39
static void compute_dar(AVRational *dar, AVRational sar, int w, int h)
Definition: vf_aspect.c:78
Main libavfilter public API header.
const char * desc
Definition: nvenc.c:63
int num
Numerator.
Definition: rational.h:59
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:92
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1113
static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
Definition: vf_aspect.c:87
AVOptions.
static AVFrame * frame
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:54
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:744
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:101
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:190
void * priv
private data for use by the filter
Definition: avfilter.h:353
var_name
Definition: aeval.c:46
AVFormatContext * ctx
Definition: movenc.c:48
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:389
AVRational dar
Definition: vf_aspect.c:61
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:379
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
AVRational sar
Definition: vf_aspect.c:62
AVRational sample_aspect_ratio
Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
Definition: frame.h:289
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
Rational number (pair of numerator and denominator).
Definition: rational.h:58
const char * name
Filter name.
Definition: avfilter.h:148
misc parsing utilities
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
#define FLAGS
Definition: vf_aspect.c:76
common internal and external API header
int den
Denominator.
Definition: rational.h:60
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:334
An instance of a filter.
Definition: avfilter.h:338
char * ratio_expr
Definition: vf_aspect.c:64
internal API functions
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_aspect.c:67
simple arithmetic expression evaluator